The present invention relates to a page buffer of a non-volatile memory device, which can output a verify completion signal even when a low-voltage fixing phenomenon of a sense node occurs.
In recent years, there has been an increasing demand for non-volatile memory devices which can be electrically programmed and erased and do not need a refresh function of rewriting data at specific intervals.
A non-volatile memory device generally includes a memory cell array in which cells for storing data are arranged in matrix form, and a page buffer for writing memory into specific cells of the memory cell array or reading memory stored in a specific cell. The page buffer includes a bit line pair connected to a specific memory cell, a register for temporarily storing data to be written into the memory cell array therein, or reading data of a specific cell from the memory cell array and temporarily storing the read data therein, a sense node for sensing the voltage level of a specific bit line or a specific register, and a bit line select unit for controlling whether the specific bit line is connected to the sense node.
While the non-volatile memory device operates, the voltage level of the sense node is fixed to a low level. This is called low-voltage fixing of the sense node. This occurs because neighboring sense nodes are shorted since page buffers are arranged densely due to a reduction in process dimensions. Accordingly, a problem arises because the voltage level of the sense node is fixed to a low level even though an attempt is made to precharge the sense node to a high level by applying a precharge signal PRECH_N.